If I had a way of knowing when the market would have low volatility, I'd throw away the shares and become a billionaire trading options.
Saying you should wait for low volatility before trading is equivalent to saying you should wait until the price is high before selling. Both statements seem to reflect common sense but neither piece of advice can be translated into an actual strategy.
The impact of HFT market making isn't that difficult to observe - all markets which have attracted such participants have seen huge falls in spreads. The spread is a tax on everyone who buys and sells in the market so lower spreads are good for everyone. (For example the cost of buying and selling a DAX future before fees was about 70 euro just 15 years ago while the spread is now typically less than a euro.)
No, because liquidity is also about tighter spreads. Since the spread is effectively a transaction fee paid to buy or sell on exchanges, shrinking it is beneficial to most market participants.
I get the argument, but it feels like the societal benefit is taken away whenever it is needed, and paid for only when it isn't needed.
[0] https://en.wikipedia.org/wiki/2010_flash_crash